-
Notifications
You must be signed in to change notification settings - Fork 499
/
serializer.py
117 lines (102 loc) · 4.46 KB
/
serializer.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
__all__ = ['Serializer', 'SerializerError']
from .error import YAMLError
from .events import (AliasEvent, CollectionEndEvent, CollectionStartEvent,
DocumentEndEvent, DocumentStartEvent, Event,
MappingEndEvent, MappingStartEvent, NodeEvent,
ScalarEvent, SequenceEndEvent, SequenceStartEvent,
StreamEndEvent, StreamStartEvent,)
from .nodes import (CollectionNode, MappingNode, Node, ScalarNode,
SequenceNode,)
class SerializerError(YAMLError):
pass
class Serializer:
ANCHOR_TEMPLATE = 'id%03d'
def __init__(self, encoding=None,
explicit_start=None, explicit_end=None, version=None, tags=None):
self.use_encoding = encoding
self.use_explicit_start = explicit_start
self.use_explicit_end = explicit_end
self.use_version = version
self.use_tags = tags
self.serialized_nodes = {}
self.anchors = {}
self.last_anchor_id = 0
self.closed = None
def open(self):
if self.closed is None:
self.emit(StreamStartEvent(encoding=self.use_encoding))
self.closed = False
elif self.closed:
raise SerializerError("serializer is closed")
else:
raise SerializerError("serializer is already opened")
def close(self):
if self.closed is None:
raise SerializerError("serializer is not opened")
elif not self.closed:
self.emit(StreamEndEvent())
self.closed = True
#def __del__(self):
# self.close()
def serialize(self, node):
if self.closed is None:
raise SerializerError("serializer is not opened")
elif self.closed:
raise SerializerError("serializer is closed")
self.emit(DocumentStartEvent(explicit=self.use_explicit_start,
version=self.use_version, tags=self.use_tags))
self.anchor_node(node)
self.serialize_node(node, None, None)
self.emit(DocumentEndEvent(explicit=self.use_explicit_end))
self.serialized_nodes = {}
self.anchors = {}
self.last_anchor_id = 0
def anchor_node(self, node):
if node in self.anchors:
if self.anchors[node] is None:
self.anchors[node] = self.generate_anchor(node)
else:
self.anchors[node] = None
if isinstance(node, SequenceNode):
for item in node.value:
self.anchor_node(item)
elif isinstance(node, MappingNode):
for key, value in node.value:
self.anchor_node(key)
self.anchor_node(value)
def generate_anchor(self, node):
self.last_anchor_id += 1
return self.ANCHOR_TEMPLATE % self.last_anchor_id
def serialize_node(self, node, parent, index):
alias = self.anchors[node]
if node in self.serialized_nodes:
self.emit(AliasEvent(alias))
else:
self.serialized_nodes[node] = True
self.descend_resolver(parent, index)
if isinstance(node, ScalarNode):
detected_tag = self.resolve(ScalarNode, node.value, (True, False))
default_tag = self.resolve(ScalarNode, node.value, (False, True))
implicit = (node.tag == detected_tag), (node.tag == default_tag)
self.emit(ScalarEvent(alias, node.tag, implicit, node.value,
style=node.style))
elif isinstance(node, SequenceNode):
implicit = (node.tag
== self.resolve(SequenceNode, node.value, True))
self.emit(SequenceStartEvent(alias, node.tag, implicit,
flow_style=node.flow_style))
index = 0
for item in node.value:
self.serialize_node(item, node, index)
index += 1
self.emit(SequenceEndEvent())
elif isinstance(node, MappingNode):
implicit = (node.tag
== self.resolve(MappingNode, node.value, True))
self.emit(MappingStartEvent(alias, node.tag, implicit,
flow_style=node.flow_style))
for key, value in node.value:
self.serialize_node(key, node, None)
self.serialize_node(value, node, key)
self.emit(MappingEndEvent())
self.ascend_resolver()